从独立应用程序轮询GMail收件箱的传入邮件的正确方法 [英] Right way to poll GMail inbox for incoming mail from stand-alone application
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问题描述
我正在轮询GMail收件箱中收到的邮件。这是我有的：
I am trying to poll GMail inbox for incoming mail. Here is what I have:
import java.util.Properties;
import javax.mail.Authenticator;
import javax.mail.Folder;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.event.MessageCountEvent;
import javax.mail.event.MessageCountListener;
import com.sun.mail.imap.IMAPFolder;
import com.sun.mail.imap.IMAPStore;
public class GmailIncomingTest {
public static void main(String[] args) {
try {
String username = "my.user@gmail.com";
String password = "mypassword";
Properties properties = new Properties();
properties.put("mail.smtp.auth", "true");
properties.put("mail.smtp.host", "smtp.gmail.com");
properties.put("mail.smtp.port", "587");
Session session = Session.getDefaultInstance(properties, new Authenticator() {
protected PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication(username, password);
}
});
IMAPStore store = (IMAPStore) session.getStore("imaps");
store.connect("smtp.gmail.com", username, password);
IMAPFolder inbox = (IMAPFolder) store.getFolder("inbox");
inbox.open(Folder.READ_ONLY);
inbox.addMessageCountListener(new MessageCountListener() {
@Override
public void messagesRemoved(MessageCountEvent event) {
}
@Override
public void messagesAdded(MessageCountEvent event) {
Message[] messages = event.getMessages();
for (Message message : messages) {
try {
System.out.println("Mail Subject:- " + message.getSubject());
} catch (MessagingException e) {
e.printStackTrace();
}
}
}
});
new Thread(new Runnable() {
private static final long KEEP_ALIVE_FREQ = 10000;
@Override
public void run() {
while (!Thread.interrupted()) {
try {
inbox.idle();
Thread.sleep(KEEP_ALIVE_FREQ);
} catch (InterruptedException e) {
} catch (MessagingException e) {
}
}
}
}).start();
} catch (Exception e) {
e.printStackTrace();
}
}
}
我想知道
推荐答案
只要您的服务器支持IDLE（gmail），那么这是一个正确的方法。将）并且您只想要通知有关新的邮件（由于程序运行）比下面的程序应该适合您的需要。如果服务器不支持IDLE和/或较旧的消息是相关的（或其他事件，如文件夹重命名等），那么您需要修改代码。看看这里有一些提示： https://github.com/salyh/elasticsearch-river-imap/blob/master/src/main/java/de/saly/elasticsearch/mailsource/ParallelPollingIMAPMailSource.java
As long your server supports IDLE (gmail will) and you want only notified about new mails (since programm is running) than the below programm should fit your needs. If server does not support IDLE and/or older message are relevant (or other events like folder rename etc) then you need to modify the code. Have a look here for some hints: https://github.com/salyh/elasticsearch-river-imap/blob/master/src/main/java/de/saly/elasticsearch/mailsource/ParallelPollingIMAPMailSource.java
import java.util.Properties;
import javax.mail.Folder;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.Store;
import javax.mail.event.MessageCountAdapter;
import javax.mail.event.MessageCountEvent;
import com.sun.mail.imap.IMAPFolder;
import com.sun.mail.imap.IMAPStore;
public class GmailIncomingTest {
private static final String username = "xxx@gmail.com";
private static final String password = "passwd";
public static void main(String[] args) {
Properties properties = new Properties();
// properties.put("mail.debug", "true");
properties.put("mail.store.protocol", "imaps");
properties.put("mail.imaps.host", "imap.gmail.com");
properties.put("mail.imaps.port", "993");
properties.put("mail.imaps.timeout", "10000");
Session session = Session.getInstance(properties); // not
// getDefaultInstance
IMAPStore store = null;
Folder inbox = null;
try {
store = (IMAPStore) session.getStore("imaps");
store.connect(username, password);
if (!store.hasCapability("IDLE")) {
throw new RuntimeException("IDLE not supported");
}
inbox = (IMAPFolder) store.getFolder("INBOX");
inbox.addMessageCountListener(new MessageCountAdapter() {
@Override
public void messagesAdded(MessageCountEvent event) {
Message[] messages = event.getMessages();
for (Message message : messages) {
try {
System.out.println("Mail Subject:- " + message.getSubject());
} catch (MessagingException e) {
e.printStackTrace();
}
}
}
});
IdleThread idleThread = new IdleThread(inbox);
idleThread.setDaemon(false);
idleThread.start();
idleThread.join();
// idleThread.kill(); //to terminate from another thread
} catch (Exception e) {
e.printStackTrace();
} finally {
close(inbox);
close(store);
}
}
private static class IdleThread extends Thread {
private final Folder folder;
private volatile boolean running = true;
public IdleThread(Folder folder) {
super();
this.folder = folder;
}
public synchronized void kill() {
if (!running)
return;
this.running = false;
}
@Override
public void run() {
while (running) {
try {
ensureOpen(folder);
System.out.println("enter idle");
((IMAPFolder) folder).idle();
} catch (Exception e) {
// something went wrong
// wait and try again
e.printStackTrace();
try {
Thread.sleep(100);
} catch (InterruptedException e1) {
// ignore
}
}
}
}
}
public static void close(final Folder folder) {
try {
if (folder != null && folder.isOpen()) {
folder.close(false);
}
} catch (final Exception e) {
// ignore
}
}
public static void close(final Store store) {
try {
if (store != null && store.isConnected()) {
store.close();
}
} catch (final Exception e) {
// ignore
}
}
public static void ensureOpen(final Folder folder) throws MessagingException {
if (folder != null) {
Store store = folder.getStore();
if (store != null && !store.isConnected()) {
store.connect(username, password);
}
} else {
throw new MessagingException("Unable to open a null folder");
}
if (folder.exists() && !folder.isOpen() && (folder.getType() & Folder.HOLDS_MESSAGES) != 0) {
System.out.println("open folder " + folder.getFullName());
folder.open(Folder.READ_ONLY);
if (!folder.isOpen())
throw new MessagingException("Unable to open folder " + folder.getFullName());
}
}
}
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